Method and apparatus for packaging large size bags in cartons

ABSTRACT

This invention relates to a method and apparatus for automatically folding a plurality of large size sheets, such as folded bags, into a &#39;&#39;&#39;&#39;W&#39;&#39;&#39;&#39; or corrugated fold and then packaging them directly into a carton in such a manner that they can be removed from the carton one at a time.

United States Patent [191 Larson et al.

METHOD AND APPARATUS FOR PACKAGING LARGE SIZE BAGS IN CARTONS Inventors: Richard T. Larson, Rogers, Ark.; William F. Leatherbury, Country Club Hills, Ill.

Assignee: Union Carbide Corporation, New

York, NY.

Filed: Nov. 26, 1974 Appl. N0.: 527,429

US. Cl. 53/21 FW; 53/120; 270/84 Int. Cl. B65B 63/04 Field of Search 53/21 FW, 120; 270/84,

[ NOV. 18, 1975 References Cited UNITED STATES PATENTS 3,656.27! 4/1972 OShea et al. 53/120 X 3,797,821 3/1974 Crenshaw 270/84 X Primary ExaminerTravis S. McGehee Attorney, Agent, or Firm-Cornelius F. OBrien ABSTRACT This invention relates to a method and apparatus for automatically folding a plurality of large size sheets, such as folded bags, into a W or corrugated fold and then packaging them directly into a carton in such a manner that they can be removed from the carton one at a time.

14 Claims, 12 Drawing Figures US. Patent Nov. 18,1975 SheetlofS 3,919,827

US. Patent Nov. 18,1975 Sheet20f5 3,919,827

Sheet 3 of 5 3,919,827

US. Patent Nov. 18, 1975 U.S-. Patent Nov. 18, 1975 Sheet 4 of5 3,919,827

US. Patent Nov. 18,1975 I Sheet50f5 3,959,827

METHOD AND APPARATUS FOR PACKAGING LARGE SIZE BAGS IN CARTONS Field of the Invention The invention relates to a method and apparatus for folding a plurality of sheets, such as large size folded bags, directly into a carton such that they can be removed from said carton individually.

Background of the invention It is well known that many people prefer to use inexpensive, disposable paper or plastic sheets or bags as a substitute for the conventional cloth or other type reuseable materials for various applications. For example, film and sheet materials made from various plastic polymers, such as polyethylene, polyvinyl chloride, polyesters and the like are enjoying wide popularity for applications normally reserved for reuseable materials. These materials, even in their film form, are strong, highly transparent, sanitary and relatively inexpensive which lends them well for use as a packaging medium. Consequently, some of the most important uses of plastic film are in the production of wrappers for food such as sandwich bags, lunch bags, food storage bags and the like. Numerous other important uses have been made of plastic film, as, for example, in trash collection such as waste basket bags, trash bags and the like.

Automatic machinery has been developed for rapidly folding and packaging a plurality of flat, flexible articles in dispensing cartons so that the articles can be removed from the carton on an individual basis. Typical of such packaging machinery is the apparatus disclosed in US. Pat. No. 3,796,428 to R. J. OShea et al, which comprises, in combination, a stacker mounted adjacent to and aligned with a complete bag dispenser, said stacker having vibration means for automatically collecting a desired number of completed bags in an aligned stack, means for conveying said aligned stack of bags to a carton loading station, means for depositing a stiffening member over a predetermined portion of said aligned stack of bags, means for folding said stack of bags, means for conveying an empty carton from a continuous conveyor of empty cartons to said carton loadingstation, and means for automatically folding and stuffing'said stack of bags into an empty carton at said carton loading station.

Another example of a packaging machine is disclosed in US. Pat. No. 3,805,482 to R. .l. OShea et al which comprises, in combination, a stack depositing station comprising means for depositing an aligned stack of articles on a conveying means; a carton loading station associated with said stack depositing station and aligned with a conveying means; conveying means comprising a movably mounted endless belt that forms a substantially horizontal movable platform surface extending between said stack depositing station and said carton loading station; means for automatically folding an aligned stack of flexible articles positioned on said conveying means; and means for automatically stuffing a folded stack of flexible articles on said conveying means at said carton loading station into an empty carton.

The packaging machines used in industry today can, with some success, use different stuffing apparatus so as to compressly pack a plurality of folded sheets into a carton so that they can be removed from the carton one at a time. One type of an individual dispensing package article known in the art is illustrated in US. Pat. No. 3,485,413 to G. A. Vestal which discloses a dispensing carton containing a stack of large size, flat, flexible articles folded into a corrugated pattern so' that each article can be individually dispensed from the carton. Other types of dispensing cartons are disclosed in US. Pat. No. 3,l95,772 to Buttery, US. Pat. No. 3,209,94l to Krake and US. Pat. No. 2,549,433 to Curry.

Although there are many well-known arrangements for packaging and dispensing flat articles of small dimensions so that they can be removed from a carton individually, there still is a need for an automaticefficient and economical way for packaging and dispensing flat articles of large dimensions made of flexible sheet material, such as large size bags or large sheets made of plastic film. Because of the large dimensions of such bags or sheets, they cannot be stacked flat and packaged in a carton since the resulting package carton would be bulky, difficult to handle and very impractical. The package article disclosed in the above-identified US. Pat. No. 3,485,413 requires the large sheets or bags to be initially folded into a corrugated arrangement and then inserted into a carton.

It is an object of this invention to provide an apparatus for automatically folding and compactly packaging a plurality of sheets or bags into a carton in such a manner that the sheets or bags can be removed one at a time.

Another object is to provide an apparatus adapted to be a component part of a packaging machine so that upon receiving a plurality of flat flexible sheets or bags, the apparatus will automatically impart a final fold to the sheets or bags just prior to compactly packaging them into an empty carton disposed thereat.

Another object is to provide an apparatus for receiving a plurality of flat, flexible folded large size bags and then automatically packaging them into a dispensing carton in such a manner that the bags can be removed one at a time through an appropriate slot in the carton.

Another object is to provide an appparatus adapted to receive a stack of flat, flexible folded bags from a high-speed bag-forming and stacking machine and then automatically impart a W fold to the stack just prior to packaging such stack into a dispensing carton.

It is another object of the invention to provide a method for folding and packaging into a small size carton a plurality of large size flat, flexible articles in such a manner that said articles can be easily and individually dispensed from said carton.

Another object of the present invention is to provide a method for folding and packaging into a small size carton a plurality of large size bags made of plastic film material in such a manner that the bage may be easily and individually dispensed from the carton.

The foregoing and additional objects will become more fully apparent from the following description and the accompanying drawings.

Summary of the Invention The invention broadly relates to an apparatus for folding a plurality of sheets directly into a carton which comprises a carriage adapted to receive and hold a plurality of sheets, said carriage having a base member with an opening disposed therein, said opening extending downward of said base member as defined by a pair of downwardly extending spaced apart side walls; means for reciprocating said carriage between a first station where said carriage will receive said sheets and a second station for discharging said sheets; at least one mandrel adapted for being disposed substantially parallel to said spaced apart side walls and across the top vicinity of said opening in the base member; means for reciprocating at least one said mandrel in a direction parallel to said side walls between a first position where it is disposed across said opening and a second position where it is retracted from said opening; at least two spaced-apart blades disposed at said second station such that when said carriage is positioned at said second station the spaced-apart blades will be disposed above and aligned substantially parallel to said side walls of the opening and spaced between said side walls in a manner such that a plane substantially parallel to and substantially midway between two adjacent blades will contain a mandrel when said mandrel is disposed at the first position; means for vertically reciprocating said spaced-apart blades within, through and from said opening in a manner such that when said carriage is positioned at the second station and at least one said mandrel is at the first position, said spaced-apart blades are advanced into a first forming site within said opening so that any sheets disposed on the carriage are folded within the side walls of said opening about the mandrel at the center of the sheets and at points between the center and ends of the sheets about the spaced-apart blades whereupon the spaced-apart blades and the mandrel are retracted from said opening to a second forming site and the spaced-apart blades are then advanced from said second forming site through said opening thereby projecting the folded sheets out of the side walls for compactly packing them into a carton whose opening is aligned directly below said side walls; In addition, synchronizing means may be added for automatically retracting the mandrel from across the opening in the carriage when the spaced-apart blades are retracted to the vicinity of the second forming site.

The invention also relates to a method for folding and packaging into a small size carton a plurality of large size flat, flexible sheets which comprises a. assembling and supporting a stack of flat, flexible sheets in a carriage having a bottom surface, said bottom surface having an opening leading to a forming throat;

b. placing mandrel across the opening leading to the forming throat;

c. advancing and folding said stack of sheets about said mandrel partly into said throat by blades spaced between said mandrel and walls defining said throat to a first forming station to thereby form the stack into a plurality of tight deep folds extending substantially transverse to the longitudinal axis of the stack;

d. withdrawing the blades from the throat to a second forming station and completely withdrawing the mandrel from the folded stack; and

e. advancing said blades from said second forming station into the folded stack sufficiently to project said stack through said throat into a sheet dispensing carton juxtaposed with said throat.

When employing two or more mandrels, then a proportional larger number of blades must be used such that the number of blades is greater than the number of mandrels by one. In addition, when an odd number of blades in excess of two is employed in the apparatus of this invention, then the center blade should be sequentially synchronized with reference to the other blades in a manner such that it is advanced to the first forming site within the opening of the carriage defined by the downwardly extending side walls, in advance of the other blades, so as to initiate the folding of the sheets about the pair of mandrels disposed on opposite sides of said center blade. Immediately thereafter or just prior to the center blade reaching the first forming site within the side walls, the pair of blades disposed adjacent to and on opposite sides of the center blade is advanced to the first forming site within the side walls in a like manner. If additional pairs of blades are employed, then each successive outward pair of blades, each disposed on opposite sides of the center blade, is advanced in a similar manner and sequence to the first forming site within the side walls of the opening until all the blades are disposed at said first forming site thereby forming the stack into a plurality of tight deep folds extending substantially transverse to the longitudinal axis of the stack. Thereafter the blades and the mandrels are retracted from said opening to a second fonning site whereupon the blades are then advanced completely through the side walls defining said opening thereby ejecting the stack, folded in a corrugated form, into a carton positioned juxtaposed with the bottom extremity of said side walls.

The first forming site or station is located within the opening at about 60% to about 90% of the depth of the downwardly extending side walls defining said opening, and preferably about of said depth. This is required so as to effectively fold the sheets within said side walls without ejecting the sheets from the exit end of the side walls. The second forming site or station is when the blades are retracted from within the opening to the upper vicinity of the opening, and preferably outside of said opening and in horizontal alignment with the mandrel(s). This step is necessary so that the mandrel(s) can be readily removed from the folded stack without effectively disturbing the folded stack.

The sequence of operation of the blades in the manner described above can be accomplished by using conventional standard means well known in the art, such as by cam and linkage means, pneumatic cylinder or electrical solenoid means, appropriately timed and sequenced by pneumatic or electrical circuitry. This blade sequence whereby the center blade is advanced first, followed thereafter with the advancement of adjacent and then outwardly successive pairs of blades, is necessary in most applications according to this invention in order to allow the stack of sheets to slide freely about the mandrels disposed adjacent to and on opposite sides of the blade without stretching or tearing the sheets as the center blade advances into .the opening in the carriage.

On the other hand, if three or more blades were to be advancedsimultaneously into the opening in the carriage, then the center blade would effectively have to stretch the width of the sheets secured between the blades disposed on opposite sides of the center blade as the center blade advanced into the opening in the carriage thereby possibly resulting in a permanent deformation of the sheets or the actual tearing of the sheets.

In alike manner, when an even number of blades in excess of two is employed, then the center pair of blades would have to be advanced into the opening in the carriage first, followed thereafter by the advancement of the adjacent pair and then successive outward pairs in the manner and sequence described above for the reason above-stated.

"When only one mandrel and one set of blades are employed, then the mandrel is adapted to be reciprocated in a direction parallel to and midway between said downwardly extending side walls of the opening in the base of the carriage and each blade is aligned substantially parallel to said side walls and substantially midwaybetween the mandrel and the adjacent side wall when the mandrel is disposed at the first position. Likewise, in the method description as set forth above, the blades in step (c) are spaced intermediate the mandrel and the walls defining the throat leading from the opening in the base.

The carriage reciprocating means is optional since thecarriage could be loaded with a plurality of sheets from a conveyor belt or the like while the carriage is positioned at a fixed site. If the arrangement of the blades above the carriage were to interfere with the loading of the carriage in this type of embodiment, then the blades could be coupled to suitable reciprocating means so that they could be horizontally or vertically retracted from above the carriage during the loading of the carriage and then advanced back into position above the carriage after the carriage is loaded with the sheets.

As used herein, a sheet shall mean a single flat, flexible layer of material; a flat, flexible folded layer of material; a flat, flexible bag; or a flat, flexible folded bag. Preferably, the invention is admirably suited for packaging flat sheets of rather large dimensions, such as large bags, which can be individually folded upon themselves before being stacked in the apparatus of this invention. Thereafter the folded sheets can be further folded according to this invention and then compactly packaged into a dispensing carton in a manner such that the sheets can be removed from the carton one at a time and then unfolded to their original size, e.g., a flat sheet of large dimensions such as a large trash bag or the like.

It is to be understood that the apparatus of this invention could be used as the finalized folding and stuffing component of an overall package machine as disclosed in US. Pat. No. 3,796,428 and 3,805,482.

The apparatus and method of the present invention willbecome apparent from the following description thereof when reconsidered together with the accompanying drawing which is set forth as being exemplary of embodiments of the present invention and is not intended, in any way, to be limitative thereof and wherein:

FIG. 1 is an isometric view of an embodiment of an apparatus of this invention.

FIG. 2 is a perspective view of a large size flexible film bag folded with two parallel longitudinal folds.

FIG. 3 is a perspective view of the bag of FIG. 1 folded with two parallel transverse folds.

FIG. 4 is a perspective view of a stack of bags folded as shown in FIG. 3.

FIG. 5 is a schematic section of a portion of a bag folding means according to one embodiment of the invention showing the stack of bags of FIG. 4 in position for forming W fold and a carton for receiving said 1 bags.

FIG. is a fragmentary portion of the folding means of FIG. 5 showing the next step in forming the stack of bags into a W fold about a centrally disposed mandrel.

FIG. 7 is a fragmentary portion of the folding means of FIG. 5 showing the stack folding operation when the mandrel is removed. I

FIG. 8 is a fragmentary portion of the folding means of FIG. 5 showing the step whereby the folded stack is advanced into a carton.

FIG. 9 is a partial schematic sectional view of the carton of FIG. 5 filled with the folded stack of bags.

FIG. 10 is a schematic section of a portion of a bag folding means according to another embodiment of the invention showing a stack of bags in position for folding and a carton for receiving said bags.

FIG. 11 is a fragmentary portion of the folding means of FIG. 10 showing the step wherein the folded stack is advanced into a carton.

FIG. 12 is a schematic view of one embodiment of a sequential synchronizing means for use in the sequential operation of the blades and mandrel(s) according to this invention.

Detailed Description In FIGS. 2 to 4 there is shown a large size flexible film bag 2 initially folded with two longitudinal parallel folds 4 and then folded with two transverse folds 6 and 6'. A plurality of such folded bags are shown aligned in a stack 8. It is to be understood that conventional folding machines, such as the Double End Folder machines manufactured by FMC Corporation and Gloucester Engineering Co., Inc., could be used to fold and arrange large size bags into a stack 8 as shown in FIG. 4.

With reference to FIGS. 1 and 5 to 9 there is shown a folding and stuffing apparatus 1 of this invention which comprises a carriage 12 coupled to a conventional pneumatic cylinder 16 for reciprocating said carrier 12 on slide rods 14. The carriage 12 comprises a platen 17 mounted on slide bearings 15 which in turn are mounted on slide rods 14 secured to the frame 10 which supports the folding and stuffing apparatus 1. A portion of platen 17 comprises the base or bottom of a .trough 9 defined by side walls 13. Trough 9 is adapted to align, and maintain aligned, the assembled bag stack 8 centrally over trough opening or aperture 19. A folding throat or horn 18 is coextensively dependingly mounted in and downward from opening 19. As shown in the drawing, the throat 18 is preferably slightly tapered although in some applications the throat can be normal to the platen 17 of carriage 12.

A mandrel 32 is coupled to a pneumatic cylinder 34 for reciprocating centrally to and fro across the entry end or opening of throat 18. Blade plunger means 20 disposed above carriage 12 comprises a pair of parallel mounted blades 21 dependingly secured to a mounting block 28 fastened to piston rod 24 slideably mounted within vertically disposed pneumatic cylinder 22. Pneumatic cylinder 22 is secured to frame 10 via mounting bracket 27 and is disposed in axial alignment with the center of mandrel 32, and throat l8. Blades 21 are spaced apart a distance one half the width of throat 18 so that each is effectively midway between one wall defining said throat 18 and mandrel 32.

An open carton 30 is juxtaposed with the throat 18 and thereby disposed for receiving the folded bag assembly 8 when pushed through throat 18. Although the carriage 12 is shown in the second station, that station being directly below the pneumatic cylinder 22, it is to be understood that carriage cylinder 16 is operable for horizontally sliding carriage 12 to the left of and away from cylinder 22 (FIG. 1) where it would then be in the first station for receiving an assembled stack of bags as shown in FIG. 4. Thus the apparatus of this invention could be positioned at the end of a conventional bag folding machine so that when the carriage 12 is disposed at its first station, it could receive the assembled stack of bags directly from the machine and then be slid over to its second station where finalized folding and packaging of the bags would occur.

A detailed operation of the apparatus 1 will be illustrated in conjunction with FIGS. 5 to 9. In FIG. 5, the carriage 12 is shown at the second station with a stack of bags 8 in trough 9 and blade plunger 20 disposed to the starting or retracted position. In FIG. 6 the blade plunger 20 is shown after the pneumatic cylinder 22 has advanced the blade plunger 20 into a first forming station or site within throat 18 thereby effectively folding the bag assembly 8 centrally about mandrel 32 and around the leading edges 23 of blades 21. At this station, the blades are advanced to about /4 of the throat 18 depth.

FIG. 7 shows the blades 21 partly retracted to a second forming station or site such that the leading edges 23 of blades 21 are aligned about the horizontal centerline of the mandrel 32 concomitantly with complete retraction of mandrel 32 from the partially folded bag assembly 8 and throat 18. Thereafter, as shown in FIG. 8, the blade plunger 20 is advanced to a third site such that the leading edges 23 of blades 21 push the W folded stack of bags completely through throat 18 and into the bottom of carton 30 aligned therewith. The blade plunger 20 is then retracted to the starting or retracted position as shown in FIG. 5 and the mandrel 32 is advanced across throat 18 preparatory to retracting carriage 12 to the first station where it will be disposed for receiving another fiat stack of assembled bags. The carton 30 can then be removed from below the throat 18 by conveyor belt means 25 and as shown in FIG. 9 be ready for sealing to yield a dispensing carton containing large size flexible bags.

FIGS. 10 and 11 show another embodiment of the invention which uses some similar parts of the apparatus shown in FIGS. 5 to 9 and, consequently, such parts are identified with the identical numbers used in said FIGS. 5 to 9. The main difference between this embodiment and the one described in conjunction with FIGS. 5 to 9 is that two parallel oriented mandrels 50 and 52 are employed instead of one and three blade members 54, 56 and 58 are used instead of two. As is apparent from the drawing, FIGS. 10 and 11 are similar to FIGS. 5 and 8, respectively, with the sequence of operation of the mandrel means 50, 52 and plunger cylinders 60, 62, 64

being as described above for applications when two or more mandrels are used. For example, FIG. 10 shows center blade 56 advancing toward stack 8 while blades 54, 58 are still in the starting or retracted position.

By employing two mandrels as shown in FIGS. 10 and 11, a longer stack of flexible bags or the like can be folded with a greater number of tight deep folds extending substantially transverse to the longitudinal axis of the stack so that the assembled folded stack can be placed in a smaller vertical height carton than would be required when using one mandrel. In a similar manner, various other embodiments of this invention would entail using three or more mandrels and a proportional larger number of blade members such that the number of blades is greater than the number of mandrels by one.

FIG. 12 shows an example of a sequential synchronizing means for use in the apparatus of this invention. Specifically, a rotary timing switch 66 is shown having a tendem arrangement of seven cam members 68, 70, 72, 74, 76, 78 and 80, each of which is aligned with and disposed such that during a complete rotation of the cam members, they will contact and thereby actuate for a specific time period, switch elements 69, 71, 73, 75, 77, 79 and 81, respectively. The switch elements 75, 77, 79 and 81 are coupled to a conventional spring centered electrically controlled hydraulic valve 82 which is operable to advance, maintain or retract blades 54, 56 and 58 via cylinders 60, 62 and 64, respectively. As shown in FIG. 12, the movement of the blades is sequentially synchronized via rotary timing switch 66 and electrically controlled hydraulic valve 82. Specifically, as the motor 84 of timing switch 66 is actuated, such as by relays from the carriage when the carriage is slid to the second station below the blades, switch element is actuated by cam member 74 thereby initiating the advancement of center blade 56 to a position designated as B whichcorresponds to the first forming site as shown in FIG. 6. Simultaneously with the advancement of center blade 56, switch element 73 is actuated to trigger switch valve 86 so as to prevent advancement of blades 54, 58. When center blade 56 advances to the vicinity of position B, and preferably when blade 56 reaches position B, switch element 71 is actuated thereby effectively preventing the movement of blade 56 while allowing the advancement of blades 54 and 58 to position B. Switch valve 86 is operable such that it will prevent the advancement of blades 54 and 58 as long as switch element 73 is actuated and then when switch element 73 is inactuated, switch element 71 will be immediately actuated to trigger switch valve 86 to allow only blades 54 and 58 to advance while preventing blade 56 from advancing. When blades 54 and 58 are advanced to position B, switch element 71 will be inactuated so as to inactuate switch valve 86 thereby permitting blades 54, 56 and 58 to move simultaneously under the control of hydraulic valve 82.

The next sequence of operation of the rotary timing switch 86 will be the actuation of switch element 77 by cam member 76 which will effectively retract blades 54, 56 and 58, via hydraulic valve 82, to position C or the second forming site. as shown in FIG. 7. As the blades 54, 56 and 58 reach the vicinity of position C,

cam member 68 actuates switch element 69 which in turn, although not shown, triggers the cylinder controlling the mandrel(s) to retract said mandrel(s) from across the opening in the carriage. Thereafter, cam member 78 actuates switch element 79 to advance blades 54, 56 and 58, via hydraulic valve 82, to position D which corresponds to the position of the blades shown in FIG. 8. The next and last sequence of the cycle of operation of the rotary timing switch 66 is the actuation of switch element 81 via cam member 80 to retract blades 54, 56 and 58, via hydraulic valve 82, to the starting position, designated as A and as shown in FIG. 5. Thus by employing the sequential synchronizing means of FIG. 12 in the apparatus of this invention, large size folded bags can be automatically and economically packaged, in a compacted form, into a carton where they can then be removed one at a time.

The operation of the sequential synchronizing means of FIG. 12 can be summarized as follows. When the sheet loaded carriage is moved to the second position,

9 motor 84 will be actuated to start rotary timing switch 66. Cam members 72 and 74 will initiate the folding and packaging operation of the apparatus by actuating switch elements 73 and 75, respectively, thereby advancing blade 56 to the first forming site designated as B while switch valve 86 is triggered, via switch element 73, to prevent movement of blades 54 and 56. Thereafter when switch element 73 is inactuated, switch element 71 is actuated by cam member 70 thereby causing the advancement of blades 54 and 58 to the first forming site B while maintaining blade 56 at the first forming site. The next sequence is the actuation of switch element 77 via cam member 76 thereby causing the hydraulic valve 82 to initiate the retraction of blades 54, 56 and 58 to the second forming site C whereupon when said blades 54, 56 and 58 are at the vicinity of the second forming site, switch element 69 is actuated by cam member 68 to retract the.mandrel(s) from across the opening in the carriage. The sequence is continued by advancing blades 54, 56 and 58 to position D via cam member 78, switch element 79 and hydraulic valve 82. The final step in the sequence is the actuation of switch element 81 by cam member 80 to effectively retract the blades 54, 56 and 58 via hydraulic valve 82, to the starting position designated as A. The cycle is then repeated for the next folding and packaging operation.

It is to be understood that the sequence of operation between the mandrel means and the plunger or blade means can be regulated by any other conventional means such as by cam and linkage means, or pheumatic cylinder means, appropriately timed and sequenced by pneumatic or electrical circuity.

The apparatus of this invention has been used to successfully package flexible 0.0015 inches (0.038 mm) thick film bags measuring 30 inches (76 cm) wide by 36 inches (94 cm) long. The bags were initially folded with two longitudinal parallel folds to a size of 7 /2 inches (19 cm) wide by 37 inches (94 cm) long. The longitudinally folded bags were then further folded with two transverse folds to yield finalized dimensions of 7 /2 inches (19 cm) by 9% inches (23.5 cm). Ten of these bags were assembled into a stack of about 1 /2 inches (3.8 cm) high as illustrated in FIG. 4 and then placed in a carriage identical to the one shown in FIG. 1. The width of the throat extending downward of the carriage was 2 /2 inches (6.35 cm) wide and the mandrel, 0.315 inch (8.0 mm) diameter, was disposed directly at the center across the opening of the throat. The blades were spaced 1.375 inches (3.5 cm) apart and each was disposed midway between a wall of the throat and the mandrel. Following the sequence of operation as discussed in conjunction with FIGS. 5 to 8, the stack of folded bags was further folded into a W form and forced into a carton measuring 2 /2 inches (6.3 cm) wide, 8 inches (20.3 cm) long and 4 inches (10.1 cm) high. The carton containing the folded bags was removed from under the carriage and sealed. For experimental purposes, the bags were then removed from the carton one at a time. Upon removal of the first bag, the remaining bags remained tightly packed within the carton thereby demonstrating that the automatic .and continuous packaging of large size bags according to this invention will provide a means whereby a large size bag can be efficiently and economically packed into a carton in such a manner that the bags can be easily and individually dispensed from said carton when needed.

It should be understood that the foregoing disclosure relates to preferred embodiments of the invention and it is intended to cover all changes and modifications of the invention which do not depart from the spirit and scope of the appended claims.

We claim;

1. An apparatus for folding a plurality of sheets directly into a carton which comprises a carriage adapted to receive and hold a plurality of sheets, said carriage having a base member with an opening disposed therein, said opening extending downward of said base member as defined by a pair of downwardly extending spaced apart side walls; at least one mandrel adapted for being disposed substantially parallel to said side walls and across the top vicinity of said opening in the base member; means for reciprocating at least one said mandrel in a direction parallel to said side walls between a first position where it is disposed across said opening and a second position where it is retracted from said opening; at least two spaced-apart blades disposed above and adapted for being aligned substantially parallel to said side walls of the opening and spaced between said side walls in a manner such that a plane substantially parallel to and substantially midway between two adjacent blades will contain a mandrel when said mandrel is disposed at the first position; means for vertically reciprocating said spaced-apart blades within, through and from said opening in a manner such that when said carriage is aligned below said blades and at least one said mandrel is at the first position, said spaced-apart blades are advanced into a first forming site within said opening so that any sheets disposed on the carriage are folded within the side walls of said opening about the mandrel at the center of the sheets and at points between the center and ends of the sheets about the spaced-apart blades, whereupon the spaced-apart blades and the mandrel are retracted from said opening to a second forming site after which the spaced-apart blades are then advanced through said opening thereby projecting the folded sheets out of the side walls for positioning within a carton whose opening is aligned directly below said side walls.

2. The apparatus of claim 1 wherein means are added for reciprocating said carriage between a first station where said carriage will receive said sheets and a second station for discharging said sheets, and wherein said at least two spaced-apart blades are disposed at said second station.

3. The apparatus of claim 2 wherein sequential synchronizing means are added for retracting said at least one mandrel from across the opening in the carriage when the spaced-apart blades are retracted to the vicinity of the second forming site.

4. The apparatus of claim 2 wherein one mandrel is employed along with one set of blades, wherein said mandrel is adapted for reciprocating in a direction parallel to and midway between said downwardly extending side walls of the opening in the base of the carriage, and wherein each blade is aligned substantially parallel to said downwardly extending side walls and substantially midway between the mandrel and the adjacent side wall when the mandrel is disposed at the first position.

5. The apparatus of claim 2 wherein an odd number of blades in excess of two is employed and wherein means is provided for sequentially advancing the center blade followed by the advancement of the adjacent and then successive pairs of outward blades to said first 1 1 forming site before the blades and mandrels are retracted to said second forming site.

6. The apparatus of claim 2 wherein said carriage has upstanding side walls for aligning a plurality of sheet placed therein.

7. The apparatus of claim 2 wherein said means for reciprocating said mandrel is pneumatic cylinder means.

8. The apparatus of claim 2 wherein said means for reciprocating said carriage is pneumatic cylinder means.

9. The apparatus of claim 2 wherein said means for reciprocating said spaced-apart blades is a spring centered electrically controlled hydraulic valve means.

10. A method for folding and packaging into a small size carton a plurality of large size fiat, flexible sheets which comprises a. assembling and supporting a stack of flat, flexible sheets in a carriage having a bottom surface, said bottom surface having an opening leading to a forming throat;

b. placing a mandrel across the opening leading to the forming throat;

c. advancing and folding said stack of sheets about said mandrel partly into said throat by blades spaced between said mandrel and walls defining said throat to a first forming station to thereby form the stack into a plurality of tight deep folds extending substantially transverse to the longitudinal axis of the stack;

d. partly withdrawing the blades from the throat to a second forming station and completely withdrawing the mandrel from the folded stack; and

e. advancing said blades from said second station into the folded stack sufficiently to project said stack through said throat into a carton juxtaposed with said throat.

11. The method of claim 10 wherein in step (b) more than two mandrels are used; wherein in step (c) the number of blades employed is one more than the number of mandrels; and wherein the center blade or pair of blades is advanced into said throat followed sequentially by the advancement of the adjacent and then successive pairs of outward blades until all of said blades are positioned at the first forming station.

12. The method of claim 10 wherein said sheets are flexible film bags.

13. The method of claim 12 wherein said bags are large size folded bags.

14. The method of claim 10 wherein in step (d) the blades are withdrawn to a position in horizontal alignment with the mandrel before the mandrel is withdrawn 

1. An apparatus for folding a plurality of sheets directly into a carton which comprises a carriage adapted to receive and hold a plurality of sheets, said carriage having a base member with an opening disposed therein, said opening extending downward of said base member as defined by a pair of downwardly extending spaced apart side walls; at least one mandrel adapted for being disposed substantially parallel to said side walls and across the top vicinity of said opening in the base member; means for reciprocating at least one said mandrel in a direction parallel to said side walls between a first position where it is disposed across said opening and a second position where it is retracted from said opening; at least two spaced-apart blades disposed above and adapted for being aligned substantially parallel to said side walls of the opening and spaced between said side walls in a manner such that a plane substantially parallel to and substantially midway between two adjacent blades will contain a mandrel when said mandrel is disposed at the first position; means for vertically reciprocating said spaced-apart blades within, through and from said opening in a manner such that when said carriage is aligned below said blades and at least one said mandrel is at the first position, said spaced-apart blades are advanced into a first forming site within said opening so that any sheets disposed on the carriage are folded within the side walls of said opening about the mandrel at the center of the sheets and at points between the center and ends of the sheets about the spaced-apart blades, whereupon the spaced-apart blades and the mandrel are retracted from said opening to a second forming site after which the spaced-apart blades are then advanced through said opening thereby projecting the folded sheets out of the side walls for positioning within a carton whose opening is aligned directly below said side walls.
 2. The apparatus of claim 1 wherein means are added for reciprocating said carriage between a first station where said carriage will receive said sheets and a second station for discharging said sheets, and wherein said at least two spaced-apart blades are disposed at said second station.
 3. The apparatus of claim 2 wherein sequential synchronizing means are added for retracting said at least one mandrel from across the opening in the carriage when the spaced-apart blades are retracted to the vicinity of the second forming site.
 4. The apparatus of claim 2 wherein one mandrel is employed along with one set of blades, wherein said mandrel is adapted for reciprocating in a direction parallel to and midway between said downwardly extending side walls of the opening in the base of the carriage, and wherein each blade is aligned substantially parallel to said downwardly extending side walls and substantially midway between the mandrel and the adjacent side wall when the mandrel is disposed at the first position.
 5. The apparatus of claim 2 wherein an odd number of blades in excess of two is employed and wherein means is provided for sequentially advancing the center blade followed by the advancement of the adjacent and then successive pairs of outward blades to said first forming site before the blades and mandrels are retracted to said second forming site.
 6. The appaRatus of claim 2 wherein said carriage has upstanding side walls for aligning a plurality of sheets placed therein.
 7. The apparatus of claim 2 wherein said means for reciprocating said mandrel is pneumatic cylinder means.
 8. The apparatus of claim 2 wherein said means for reciprocating said carriage is pneumatic cylinder means.
 9. The apparatus of claim 2 wherein said means for reciprocating said spaced-apart blades is a spring centered electrically controlled hydraulic valve means.
 10. A method for folding and packaging into a small size carton a plurality of large size flat, flexible sheets which comprises a. assembling and supporting a stack of flat, flexible sheets in a carriage having a bottom surface, said bottom surface having an opening leading to a forming throat; b. placing a mandrel across the opening leading to the forming throat; c. advancing and folding said stack of sheets about said mandrel partly into said throat by blades spaced between said mandrel and walls defining said throat to a first forming station to thereby form the stack into a plurality of tight deep folds extending substantially transverse to the longitudinal axis of the stack; d. partly withdrawing the blades from the throat to a second forming station and completely withdrawing the mandrel from the folded stack; and e. advancing said blades from said second station into the folded stack sufficiently to project said stack through said throat into a carton juxtaposed with said throat.
 11. The method of claim 10 wherein in step (b) more than two mandrels are used; wherein in step (c) the number of blades employed is one more than the number of mandrels; and wherein the center blade or pair of blades is advanced into said throat followed sequentially by the advancement of the adjacent and then successive pairs of outward blades until all of said blades are positioned at the first forming station.
 12. The method of claim 10 wherein said sheets are flexible film bags.
 13. The method of claim 12 wherein said bags are large size folded bags.
 14. The method of claim 10 wherein in step (d) the blades are withdrawn to a position in horizontal alignment with the mandrel before the mandrel is withdrawn from the folded stack. 